Less than 4% of study participants reported taking a folic acid or vitamin B12 supplement, according to the study.

One in eight adults in Ireland over the age of 50 aren’t getting enough vitamin B12 from their normal diets while one in seven are deficient in folic acid, but researchers from Trinity College Dublin argued that this could be improved by adopting a mandatory food fortification policy similar to the US.

The study, published in the British Journal of Nutrition​​,​ recruited a nationally representative sample of community-dwelling adults aged 50 and older living as part of The Irish Longitudinal Study on Ageing (TILDA).

Researchers collected general data from study participants (n=5895) including sex, age, residence, habitation status (living alone yes/no), income, as well as smoking and drinking habits. Data collection also included donating a blood sample. In total, folate measurements were available for 90.7 % (n 5350) and B12 measurements were available for 88·5 % (n 5219) of these participants.

The range of the study participants was 50 to 98 years of age (mean age=63.6 years). The proportion who reported currently consuming alcohol was 76.8 %, whereas 15.6 % were current smokers.

Senior author of the study, professor Anne Molloy, noted that mandatory folic acid fortification of certain foods in the US has been effective policy and something Ireland’s public health sector should consider.

"This study shows a surprising level of inadequate folate among older persons, despite many years of voluntary folic acid fortification of certain foods on the Irish market,”​ Molloy stated.

“However, in countries such as the US, mandatory folic acid food fortification for the past 20 years has prevented millions of cases of folate deficiency without any proven adverse effects. Irish public health authorities need to act on the facts from studies such as ours," ​she said.

Results​

Out of the more than 5,000 participants, fewer than 4% reported taking a dietary supplement of either vitamin, according the study. The highest rates of vitamin B12 and folate deficiencies were observed in participants aged 80 years and older.

“Older adults can be at a particular risk of deficiency owing to increased malabsorption from atrophic gastritis, infection or medication interaction,”​ researchers wrote.

Researchers added that sex and income played a role in vitamin B12 and folate levels among participants.

“Interestingly, we also observed that men and those with a lower asset wealth also had lower folate and B12 concentrations. It has been reported that men often display a lower B-vitamin status than women, which in some studies has been attributed to a higher intake of supplements (which also appears to be a factor in the current study).​

“In addition, it has been observed that older men tend to have a poorer awareness of healthy diet recommendations compared with women who were also more likely to have healthier dietary patterns.”​

Effectiveness a mandatory fortification policy​

Researchers argued that Ireland’s voluntary fortification policy (cereal, grains, or flour enriched with vitamins and minerals such as folate and B12) contributed to the deficiency rates found in the nationally representative sample.

“These data are in stark contrast to countries with mandatory fortification (of enriched cereal grains or flour) such as the US where rates of low folate status have been reported in only 1-2 % of those aged ≥60 years (post-fortification),”​ researchers wrote.

Lead author of the study and research fellow at TILDA, Dr Eamon Laird, hopes the study finding will help inform public health policies, particularly the adoption of mandatory folic acid and/or vitamin B12 fortification in food products such as cereal, grains, and bread products.

“To place our findings in context, in a country such as the United States where mandatory folic acid fortification occurs, rates of low folate status are around 1.2% in older adults compared with 15% in Ireland,"​ Dr Laird commented.